text: // SPDX-License-Identifier: GPL-2.0
  /*
   * This is a good place to put board specific reboot fixups.
   *
   * List of supported fixups:
   * geode-gx1/cs5530a - Jaya Kumar <jayalk@intworks.biz>
   * geode-gx/lx/cs5536 - Andres Salomon <dilinger@debian.org>
   *
   */
  
  #include <asm/delay.h>
  #include <linux/pci.h>
  #include <linux/interrupt.h>
  #include <asm/reboot_fixups.h>
  #include <asm/msr.h>
  #include <linux/cs5535.h>
  
  static void cs5530a_warm_reset(struct pci_dev *dev)
  {
  	/* writing 1 to the reset control register, 0x44 causes the
  	cs5530a to perform a system warm reset */
  	pci_write_config_byte(dev, 0x44, 0x1);
  	udelay(50); /* shouldn't get here but be safe and spin-a-while */
  	return;
  }
  
  static void cs5536_warm_reset(struct pci_dev *dev)
  {
  	/* writing 1 to the LSB of this MSR causes a hard reset */
  	wrmsrl(MSR_DIVIL_SOFT_RESET, 1ULL);
  	udelay(50); /* shouldn't get here but be safe and spin a while */
  }
  
  static void rdc321x_reset(struct pci_dev *dev)
  {
  	unsigned i;
  	/* Voluntary reset the watchdog timer */
  	outl(0x80003840, 0xCF8);
  	/* Generate a CPU reset on next tick */
  	i = inl(0xCFC);
  	/* Use the minimum timer resolution */
  	i |= 0x1600;
  	outl(i, 0xCFC);
  	outb(1, 0x92);
  }
  
  static void ce4100_reset(struct pci_dev *dev)
  {
  	int i;
  
  	for (i = 0; i < 10; i++) {
  		outb(0x2, 0xcf9);
  		udelay(50);
  	}
  }
  
  struct device_fixup {
  	unsigned int vendor;
  	unsigned int device;
  	void (*reboot_fixup)(struct pci_dev *);
  };
  
  /*
   * PCI ids solely used for fixups_table go here
   */
  #define PCI_DEVICE_ID_INTEL_CE4100	0x0708
  
  static const struct device_fixup fixups_table[] = {
  { PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY, cs5530a_warm_reset },
  { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, cs5536_warm_reset },
  { PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE, cs5530a_warm_reset },
  { PCI_VENDOR_ID_RDC, PCI_DEVICE_ID_RDC_R6030, rdc321x_reset },
  { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CE4100, ce4100_reset },
  };
  
  /*
   * we see if any fixup is available for our current hardware. if there
   * is a fixup, we call it and we expect to never return from it. if we
   * do return, we keep looking and then eventually fall back to the
   * standard mach_reboot on return.
   */
  void mach_reboot_fixups(void)
  {
  	const struct device_fixup *cur;
  	struct pci_dev *dev;
  	int i;
  
  	/* we can be called from sysrq-B code. In such a case it is
  	 * prohibited to dig PCI */
  	if (in_interrupt())
  		return;
  
  	for (i=0; i < ARRAY_SIZE(fixups_table); i++) {
  		cur = &(fixups_table[i]);
  		dev = pci_get_device(cur->vendor, cur->device, NULL);
  		if (!dev)
  			continue;
  
  		cur->reboot_fixup(dev);
  		pci_dev_put(dev);
  	}
  }
  
  